In general, cell migration refers to movement of a living organism or individual cells due to various physical, chemical or biological stimulus, and is deeply related to various diseases and biological phenomena in human body such as infection of AIDS, germs, bacteria or the like, arteriosclerosis, arthritis, periodontitis, psoriasis, cancer, multiple sclerosis, male sterility, asbestos poisoning, or ozone poisoning.
However, an evaluation assay for cell migration according to the conventional art is mostly directed to two-dimensional cell migration, and only crawling of cells can be observed by using the conventional evaluation assay. However, cells actually exist three-dimensionally in reality, and thus in many cases, results that are different from actual phenomena are acquired from the conventional evaluation assay.
Assays for analyzing three-dimensional cell migration, histogenesis, form changes, or cell differentiation or the like have been developed overseas, but the assays still have limitations in exposing cells under particular conditions or copying actual three-dimensional migration occurring inside a living organism. Moreover, it is difficult to effectively evaluate and quantify an experimental result. When introducing a scaffold formed of an extracellular matrix (ECM) between microfluidic channels, advantages of microfluidic technology may be maintained, and at the same time, cell reaction may be mimicked three-dimensionally under an evaluation environment for evaluating, for example, cell migration and form changes, histogenesis, or cell differentiation. The above-described advantages are disclosed in International Patent Application No. WO2009/126524. This related art succeeded in mimicking formation of new blood vessels in 3D by introducing a collagen scaffold, which is one kind of ECM, between microfluidic channels. Also, the related art also discloses results of research on reaction between an endothelial cell of a blood vessel and a cancer cell, reaction between a liver cell and an endothelial cell of a blood vessel, and reaction of nerve cells.
Microfluidic technology may provide a micro environment around cells, and allows real-time observation of the cells and accurate quantification of reaction of the cells, reduction in the amount of cells or samples used, and evaluation of various experimental conditions. In addition, a technique of integrating a scaffold may induce a cell three-dimensionally, and allows for cultivation of cells according to various directions, for example, inwardly into the scaffold or on two sides of the scaffold. Thus, culturing of diverse cells at a time is enabled, and this allows research of an interaction between cells and research of an interaction between a cell and the scaffold itself, and the cells cultivated in the above-described manner may also be used in developing a medical material. Moreover, the effect of various materials such as nano-materials, medication, or protein, on a cell may be evaluated three-dimensionally.
However, a microfluidic platform according to the related art requires a pillar array having several tens to hundreds; a to fix space between a scaffold and a channel. If a pillar is not present, a scaffold may leak through a channel, and thus may not be used. For reference, a scaffold is mostly in the form of liquid and is hardened after being injected to a particular position in a channel, and a pillar is needed to confine the injected scaffold at a particular position before the scaffold is hardened.
However, the microfluidic platform described above has limited area for reaction of cells due to the pillar that prevents leakage of the scaffold, and mass production of the microfluidic platform is difficult. Also, the pillar is continuously seen during an observation process and thus disturbs quantification, and moreover, the main problem lies in that cells first react with the pillar rather than with the scaffold.